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Jignesh Parmar has completed M.Tech (Power System Control), B.E (Electrical). He is member of Institution of Engineers (MIE), India. He has more than 13 years experience in transmission & distribution-energy theft detection and maintenance electrical projects.

19 Comments

edwin

Apr 09, 2019

Can you please provide earthing calculation formula using lattice instead of earth electrode

Dear Sir,
I have seen practice of providing plate electrode for main equipment earthing (HT switchgear, transformer body etc) while pipe electrodes for whole earthing system why plate electrode we used for main equipment (as we know pipe electrode is superior to plate electrode).

Article for calculating nos. of electrodes of different types is very much useful to designers like me. I would like to draw your attention to formula for calculating resistance bare earthing conductor or strip, where diameter of conductor is to be used. As provided in IS:3034, twice the diameter of conductor is to be taken, whereas for bare strip only width of strip is to be taken. In example given in the article, probably single diameter of conductor is used. Moreover, formula starts with 100x(soil resistivity – raw), whereas in calculation only 65 (ohm-m) is shown and is not multiplied with 100. I am unable to get 1.7 ohm while making calculations as per formula. Kindly check up and revert back.